Three-dimensional seismic analysis based on FE modeling using 3-D survey incorporating spatial variability of stiffness

Abstract Japan is one of the most earthquake-prone countries in the world, where a significant portion of disaster-related losses can be attributed to structural collapses. Thus, the inspection of geo-structures related to these earthquakes is important. Although conventional inspections are conducted by two-dimensional analyses, the actual behaviors of the structures are affected three-dimensionally. This has led to an increase in the demand for three-dimensional analyses. A three-dimensional survey has recently been developed, using an unmanned aerial vehicle (UAV), which has made the rebuilding of the three-dimensional shape of structures easier. Despite the development of this technique, it has not been adopted for the design of geo-structures. In this study, for the purpose of incorporating the three-dimensional survey technique into the design of geo-structures, an earth-fill dam is surveyed three-dimensionally by a drone, and a three-dimensional finite element model (FEM model) of the dam is made based on the survey results and the newly developed modeling approach. The spatial distribution of the ground stiffness is estimated based on screw weight sounding (SWS) test results, and then applied to the 3-D FEM modeling. Gaussian process regression (GPR), which serves as a geostatistical interpolation framework to transform sparse field measurements into continuous three-dimensional material property distributions for the FEM model, is employed for the spatial interpolation of the ground stiffness. Finally, the FEM model is applied to a seismic response analysis, and the locations of high acceleration and high shear stress inside the earth-fill dam are identified.